It is the long range objective of this project to study the rhodopsin molecule and other molecules, such as retinal and retinol binding protein, which are involved in the visual process in order to attempt to elucidate further information regarding the relationships between their structures and their functions. The topics of current interest are studies on the self-association of retinal in organic solvents and the effects of retinal isomerization on this association and studies on the association of retinol binding protein and prealbumin.